The present invention relates to a device for detecting remaining quantity of rolled papers in a device such as a printer.
In such a device using the rolled paper as the printer, it is necessary to be informed that the remaining quantity of the rolled paper is little, even if a rolled paper different from a previously used rolled paper in diameter of the core is used.
In a conventional detecting device, a detecting plate for operating a detector switch must be moved in accordance with the change of the diameter of the core of the rolled paper. In order to move the detecting plate, a fixing screw is released, the detecting plate is moved along a guide, and the screw must be turned to fasten the plate. Therefore, the adjusting operation is troublesome.
An object of the present invention is to provide a detecting device which may be easily adjusted in accordance with the change of the diameter of the core.
According to the present invention, there is provided a device for detecting remaining quantity of rolled papers comprising, a housing having a bottom for supporting a rolled paper, detector means for detecting a peripheral position of the rolled paper supported on the bottom when the peripheral position approaches an inner end of the paper and for generating an output signal, positioning means for positioning the detector means at a position dependent on a radius of a core of the rolled paper, a control circuit responsive to the output signal for informing that the rolled paper reaches the inner end.
The detector means is at least one photodetector mounted on a rotatable lever, and the positioning means is notches provided in the housing and a movable knob having a lug engaged with one of the notches.
The photodetector comprises a light emitting element for emitting light to a side of the rolled paper, and a light receiving element for receiving the light reflected from the side.
These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.